The present invention relates to a method and apparatus for processing a substrate by spraying a processing solution onto the substrate.
The process of manufacturing a photo mask used in a liquid crystal display device, a semiconductor device or in the manufacture thereof includes a lithography step for forming a circuit pattern on a substrate such as a glass substrate, a semiconductor wafer or a quartz substrate by using the photo mask.
For forming a circuit pattern on the substrate in the lithography process, the steps of forming a resist pattern on the substrate, etching the substrate by using the resist pattern as a mask, removing the resist pattern after the etching step, and forming a film on the substrate having the resist pattern removed therefrom are repeated a plurality of times.
Where the substrate is a photo mask used in the manufacture of a liquid crystal display device or a semiconductor device, an insoluble resist that is unlikely to be dissolved in a solvent is used for forming a pattern. If the pattern is formed by using the insoluble resist, it is difficult to peel off the pattern by the ordinary method. Thus, a plasma ashing is employed for removing the resist pattern.
However, the plasma ashing invites an increased manufacturing cost and a low through-put.
Under the circumstances, a new technique replacing the plasma ashing is disclosed in, for example, Japanese Patent Disclosure (Kokai) No. 6-29270 and Japanese Patent Disclosure No. 6-291098. Specifically, it is disclosed that the resist pattern is peeled off by using a mixed solution consisting of sulfuric acid and hydrogen peroxide solution, followed by supplying a pure water onto the substrate for the rinsing treatment.
However, the prior art exemplified above is defective in that, in rinsing the substrate with a pure water after peeling of the resist pattern off the substrate with the mixed solution, the pure water tends to bring about a dissolving reaction with the sulfuric acid remaining on the substrate. What should be noted is that the dissolving reaction brings about the mist generation and scattering of the sulfuric acid.